Method of and means for drying



Oct. 19 k1926.

. 1,603,760 E. A. FURKERT METHOD 0F AND MEANS FOR DRYNG Filed sept; 17, 1925 3 Sheets-Sheet 1 Oct. 19 1926.

A E. A. FURKERT METHOD OF AND MEANS FOR DRYING Filed sept. 17 s sheets-sheet 2 Oct. 19 1926. 1,603,760

E. A. FuRKER-i METHOD OF AND` MEANS FOR DRYING Filed sept. 17, 1925 sheets-sheet 3 1% R k m om@ E o oo u) m m l m KN oo 'o l E I a y N qq N d 'N l 9&1

1Q N w N weafw y atented Uct. 19, 1926.

STATES f PATENT OFFICE.

ERNEST A. FURKERT, OF CHICAGO, ILLINOIS.

METHOD or am) MEANS ronpmrme.

Application tiled September 17, 1923. Serial No. 663,092?.`

drying. In the drying process volatile vapors of a dangerous nature are given olf. The matter of continuously removing and dissipating these without explosion and without impairing the quality ofthe work, has presented a difficult problem. Another v difficulty has been in distributing the heat uniformly through. the drying chamber. The burners have been usually arranged inside the oven itself and hot spots and nonuniform heat application has resulted, which causes discoloration and -otherwise impairs the quality of the work. Various provisions including the delivery of air into the upper'part of the chamber for the purpose of setting up a continuous movement within the chamber,l other than that caused.

by the circulation of the heating medium, have been made in such arrangements.l in attempting to avoid hot spots an'd insure umform drying. 'llhese have proceeded on the aso theory of counteracting rather than 'removy ing the objectionable feature of the drying process. Y

I provide for utilizingthe vapors given if in the drying process for maintaining: the desired drying temperature, more specilicaL ly, I utilize the vapors `given off in the drying process in the heating of the drying oven itself, and I provide for doing this without danger of explosion. By utilizing these vapors, or gases in heating the oven, I dispose of the problem of removing an'd dissipating said vapors and in addition the amount of fuel required to maintain the desired drying temperature is decreased with an accompanying decrease in-the cost of To distribute the heat uniformlylthrough the oven, I provide for heating the air or other drying medium in a heater or chamber outside the oven, and then 'delivering the heated medium to and distributing it uni'-v formly, through the oven. The. disadvantages o`f arranging the burner or heater in the oven and the objectionable results of such an arrangement are thereby avoided.

operation.'

Another feature is an improved apparatus for carrying out the invention.

The invention also embodies important structural improvements which are made the subject-matter of certain of the appended claims. These include certain 'details in the heater and in the connections between the heater and the oven.

To acquaint those skilled in the art with the nature of the invention, Ishall now describe with the aid ofthe accompanying drawings the method `of the invention and apparatus for carryingit out.

In the drawings 3 Figure l is a more or less diagrammatic longitudinal section of a drying oven for carrying out the invention, showing the heater in elevation;

Fig. -2 shows the heater= and its connections with the oven in end elevation and the oven in vertical transverse section;

Fig. 3 is a longitudinal vertical section thrugh the heater; an'd- Fig. 4 is `a vertical transverse section on line i- 4 of Fig. 3. Y

The apparatus selected for illustration comprises a drying oven-5 supported bylegs 13 and havinginlet and outlet openings 6-6 in its opposite ends 7-7 and traveling through the oven by way of said inlet and outlet openings 6 6 is an endless conveyor 8. The structural details of oven 5, its insulation and the structural details of conveyor 8 may 'take any suitable or preferred' form. Per se they form no part of the present invention. Conveyor 8 may be driven in any suitable or desired manner as through one of the sprockets 9 at its opposite ends and the lithographedior lacquered metal plates or other prepared stock, to be dried, may be fed into position between arms 10 by means of a suitable feeder, directly from the press or preparing process. or in any other manner.

Conveyor 8 passes the prepared stock, shown in the form of sheets 12, continuously through the interior of heating or drying chamber 5 where same is heated to the desired drying temperature for the desired time interval. The vertical arrangement of i sheets. 12 inv their movement through .the oven not onlyfpermits uniform 'heat application -to the entire prepared surfaces of same but permits the vapors or gases given of in drying to leave'the material without n.0

i unduly collecting thereabout. This arrangement may, however, be varied and, modified as desired. Inlet and outlet openings 6-6 may be closed by any suitable sheets 12 into and out of the oven. Pipes for projecting blankets of air across the inlet and outlet openings to close same, yet pererably of sheet steel although it may formed of other suitable material. Shell 16 y is connected mit the sheet to venter and leave the oven have been provided before.

The interior of drying chamber or oven `5 is heated by a heater 15 a ranged outside the oven and longitudina ly therealong. Heater 15 comprises a circular shell 16 prel-B is supported by legs 17 upon common supporting surface 18 and has aul open inlet end and a tapering dischargeend opening into a drum 19 within which a suitable fan or impeller revolves. An internal shell 20 mounted axially in shell 16 forms an annular space 21 between it and the interior of shell 16. Shell 20 is secured at its Outer end in an annular ring 22 secured in and elosingathe outer end of annular space 21.

' A p te or` closure '24 covers the outer end of shell 20, said plate having apertures 25 through which the air which sup rts combustion of the fuel directed axial y into the outer end of shell 20 from a nozzle or jet 27. Nozzle 27 is shown formed integral with the central portion of closure V24. It has outlets or jet oenings 26 at its inner end and y a pipe line 28 with an illuminatin gas line, for example, lalthough it may e suppliedl with any other suitable fuel. The fuel is ignited in any suitable manner as it issues from outlets or jet openings 26 into shell 20. A disc 30 having an outturned lug or linger pieceJ for rotating it about the outwardly projecting nozzle forminglhub of plate 24 upon which it is secured by retention means 32, has openings '31 similar to openings 25 formovement into and out of register with openings 26 by rotation of disc 25, to control the air supply through openings 26.

The interior of shell 20 is lined with fire brick or other suitable refractory material preferably although not necessarily in the form of rings 35. Each ring is open at one end and has a wall 36 at its opposite end. Walls 36 form transverse partitions at spaced intervals through the interior of the shell 20, and said walls are alternately provided .with concentrically and non-concentrically disposed openings 37 and 38 for giving the lame and products of combustion issuingfrom nozzle 27 a tortuous course through shell 20 to insure roper mixing of the fuel and eifective heating of the wall of the inner shell.

'Fan or impeller drum 19 is supported quer7 or other substance from the interior l of oven 5 through outlets 50 leading from the top of the oven at suitably arranged points, to a duct or conduit 52. 'Conduit 52 extends longitudinally along the top of oven 5, is turned down along the heater end of the oven and opens at 53 through an inlet 54 into the outer end of annular space 21. Inlet 54 is provided with a damper'55 for controlling the deliveryof the vapors or gases given off inthe drying process and other fluid contents of oven 5 to the heater. Air

admitted through a fresh air inlet 56 in thebottom yof the outer end of shell 16 supports combustion of the substances recirculated from the oven to-the heater. Inlet 56 is controlled by aV suitable gate or slide valve 57.

The Huid recirculated into the heater through inlet 54 is heated by mixer and burner shell'20 and passing forwardly encounters the ignited 'fuel issuing from the inner end off shell 20. Combustion of the combustible vapors and gases of the recirculated fluid at this point is continuous so that the vapors and gases are not permitttd to accumulate at any point in the apparatus, thus reducing danger of explosion and assists in the heating action of the burner and decreases the amount of fuel necessary through line 28 to maintain the drying temi discharge end ofthe heater and directed upA through outlet 60 leading from drum 19 into a duct or conduit 62. Duct 62 is preferably flat and of a length and width substantially that of oven 5 so as to discharge uniformly up over all sheets 12 or other work in the loven andlias a number of suitably arranged transversely extending outlets 65. The inner end of shell 16 beyond shell 2O which is where combustion of the circulated vapors takes place is preferably provided with a fire brick or other suitable lining 68.-

v This lining 68 may be made up of fire brick or other refractory rings having transverse partition forming walls with staggered openings 75 and 76 for insuring proper mixing and combustion at this point. The amount of air admitted through inlet 56 may be just suliicient to support combustion of the recirculated vaporor it may bein excess of that if desired.

In carrying out the invention the air or other drying Huid is heated by burner 27 and projected by fan 19 into a duct 62 from Which it discharges uniformly through outlets up over the work. The volatile vapors or gases given olf in the drying process are recirculated through duct 52 back through the heater where those 'that are combustible aid in maintaining the temperature and any that are not combpstible are\heated and projected back-to the oven. The heater may be maintained at afmuch higher temperature than the oven and upon entering the oven the drying medium is of a uniform temperature as distinguished from the nonuniform temperature resulting in the open where the drying medium is heated there.-

The recirculating of the vapors an'd gases given olf in the dry-ing process through the heater disposes of the problem of removing and dissipating said gases and does it Without the danger usually attending the handling of said gases and -at the Sametime decreases the fuel necessary with an accompanying decrease in cost-of operation. This is an important aspect of the invention. Arrangement of theyheater outside the. oven ypermits higher temperaturesin the heater than in the oven. This insures a uniform temperature of the drying medium upon entrance into the oven ahd the higher temperature permitted in .the heater insures proper cracking of the recirculated vapors. These are also important aspects ofthe invention.

The arran ement of the fan or impeller between 'the urner and the outlet duct to the oven enables the setting up of a pressure in the outlet duct Without backing up into the burner or fuel supply line.

. ll do not intend to be limited to the precise details shown and described.

l claim:

l. ln combination, a drying chamber, a heater, a fuel combustion chamber in the heater, an annular space about said chamber, a refractory checker Work in the fuel combustion chamber, a refractory checker Work in the heater beyond the fuel combustion chamber, means for recirculating the vapors given od' -in drying to the space about the fuel combustion chamber and an air inlet to said space.

2. An apparatus of the character specified comprising an oven, a casing having an outlet and an inlet in communication with the oven sothat products of combustion may.

pass from the casing through said outlet into the oven Iand return from the latter through the inlet to the casing, a combustion chamber in said casing in communication with the interior thereof disposed to intercept the products of combustion returningthrough said inlet, a burner for said chamber, and

. cause the products .ed comprising an oven,

means in communication With the casing to of combustion to follow the path indicated.

3. An apparatus of the character specified comprising an oven, a casing having an outlet and an inlet in communication with the oven so that products of combustion may pass from the casing through said outlet into the oven and return from the latter through the inlet to the casing, a combustion chamber in said casing in Acommunication with the interior thereof, a burner for said chamber, and means in communication With the casing to cause the products of combustion to follow the path indicated.

4t. An apparatus of the character specia casing having an outlet and anV inlet in communication with the oven so that products of combustion may pass from the casing through said outlet into the oven and return from the latter through the inlet to the casing, a combustion chamber in said casing in communication with the interior thereof disposed to intercept the products of combustion returning through said inlet, a burner for said chamber, said casing having an opening for the supply of air thereto, and means in communication with the casing to draw fuel to the burner, air through said opening, and to lcause the productsdof combustion to follow the path indicate v 5. An apparatus of the character specified comprising an oven, a easing having an outlet and an inlet in communication with the oven so that products lof combustion may pass from the-casing through said out-let into the oven and return from the latter through the inlet to the casing, a combustion chamber in said casing in communication with the interior thereof disposedto' intercept the products of combustion returning through said inlet, a burner for said chamber7 said casing having an openingl for the supply of fuel thereto, and a fan in said casing operable to draw fuel to the burner, air through said opening and to cause the `products of combust-ion to follow the path indicated.

6. An apparatus of the character specified having means providingan endless passageway including an oven, a burner in said passagewayf, means to cause the products of combustion from said burner to travel in said passageway so as to recirculate and convey combustible vapors which may be given off by articles being treated in said oven, s i that such products will reach said burner for combustion.

7. An apparatus of the character specied having means providing an endless passage- Way including an oven and. a casing, a. burner in said'casing, and a fan in said casing to cause the products of combustion from said burner to travel in said passage so as to recirculate and convey combustible vapors which may be given off by articles being treated in said oven, so that such products will reach said burner for combustion.

8. A ste in the art of drying articles coated with) materialy which in the process of drying gives o explosive vapors, which consists in subjecting such articles to the action of acirculatng heated medium to dry the same and to take Iup such explosive vapors, and contnuousl conducting such dry- 10 mg medium combin with such vapors back to the soure of heat, thereby utilizing such vapors as an additional fuel supply and preventing their accidental explosion.

In witness whereof, I hereunto subscribe 15 my name this 15 d'ay of September, 1923.

ERNEST A. FURKERT. 

